It is not easy to follow orangutans through the forest. They swing through the trees with the greatest of ease, forcing the poor lumbering biped to push through brush or wade through swamps, risking life-threatening encounters with insects, snakes, crocodiles and more, to keep up.
But this was the life that the young primatologist Biruté Galdikas, who has died aged 79, chose in 1971, and in the decades that followed she added the third and fourth dimensions to the very flat image of these critically endangered animals that scientists had held until then.
